HIV may be detected in 3-12 weeks or 2-6 weeks depending on the test reagent. HIV testing reagents are categorized into third and fourth generation reagents. 1. Third-generation reagent: applying the third-generation reagent test for AIDS, which is the most commonly used test at present, is the AIDS-specific antibody test, which can be detected as soon as 3 weeks after the infection, and the vast majority of people can be checked for antibodies 3-12 weeks after the infection, so the window period for the antibody test is 3-12 weeks after the high risk. 2. Fourth generation reagent: HIV-specific antibody combined with P24 antigen detection, or known as the fourth generation of testing, can simultaneously detect HIV antibodies and antigens, the vast majority of people can be detected 2-6 weeks after infection, so the window period of time is 2-6 weeks after high-risk exposure. If you feel unwell, you need to seek medical attention as soon as possible and under the guidance of your doctor for standardized examination and treatment.